THE MYXOSPORIDIA, OK PSOROSPERMS OF FISHES. 69 



the name of the i^erson collecting-, and particularly that of the person 

 identifying it. 



Microscopic technique. — Especially the fixation process and the stains 

 found most useful should be mentioned. 



Parasite. — Besides the indications contained in the above outline for 

 arrangement, the gaps in the Tabular Key (pp. 138-165) otfer an invit- 

 ing field for future work. One other point should receive most careful 

 attention, viz, a close comparison of the (at present probably unduly 

 multiplied) forms habitant upon the same host, and especially those in 

 the same organ of the same host. In this way a few years will suflice 

 to condense the present synonymy to its proper dimensions. It may 

 be added that even the dimensions of the spores — the most accurate 

 of all data — are sometimes omitted. 



Effects and epidemics. — Above all, attention should be directed to 

 gathering accurate data as to the extent, the species of fishes affected 

 and those exempt, the territory invaded, the season, as far as possible 

 the relative potency as causative factors of temperature, water pollu- 

 tion, etc. The effects of all remedies tried, whether successful or not, 

 should of course be recorded. 



Reduction of measurements. — The older authors recorded their meas- 

 urements in thousandths of a line.' I have reduced these to yu's. 

 Owing to the number of inches (also, consequently, of lines) in use in 

 Germany, the original measurements are quoted in parenthesis. In 

 1853 Eobin ^ reduced the German measurements to decimals of a milli- 

 meter. He assumed 1" ' = 2.25 mm. Biitschli ^ adopts the same equiv- 

 alent for the " Linie " (" '). Wherever my results differ from Eobin's 

 I have noted his figures in parenthesis along with the original measure- 

 ments. 



The following are the calculations and the resulting equivalents 

 adopted : 



Ono rnissian foot = 1-0298 English feet. 



One Prussian inch ^ 1-0298 English inches. 



One ra. = 39-371 English inches r= 38-2317 Prussian inches. 



One mm. = 0-0382317 Prussian inches =^ 0-45878 Prussian linos. 



Thus 1 "Linie" = 2-18 mm. nearly instead of 2-25 mm. 



Fortunately the discrepancies are slight. All spore-measurements 

 are in yu's; cyst measurements in decimals of a millimeter. 



As regards the translations, I am responsible for all, with the excep- 

 tion of Kolesnikofif's article the translation of which was made by 

 Mr. Israeli, of the Surgeon -General's Library. Dr. Eobert Stein, of 



' In the only case where I could find a direct comparison hetween Miiller's "Linie" 

 and the millimeter, viz, Miiller's translation of Gluge's y-rflu of a mm. for (!ht;/ca 

 anomala (Gluge, P.uU. Acad. Roy. Helg., 1838, v, p. 774; Miiller, Miiller's Archiv., 

 1841, p. 491), as 0-0020'", Miiller regards the former as etxual to 2 mm. 



'^ Hist. Nat. des V6g(5t. Parasites. 



*&6e Chloromyxuvi mucroHatum{T^. 264), 



